Kylie Jenner and Jennifer Lopez were among the many guests who paid tribute to hairstylist Jesus Guerrero at his funeral ... TMZ has learned.

Sources with direct knowledge tell TMZ ... Jenner and Lopez attended their longtime stylist's funeral services in his hometown of Houston on Sunday. We're told Jesus' family and many friends from the glam community also attended.

Jesus was known for having close ties with Katy Perry ... and while she could not attend the services because she's currently rehearsing for her upcoming tour, we're told she has been in touch with his family.

Katy posted about Jesus just a couple weeks after he passed ... calling him a warm and welcoming presence.

We broke the story ... Kylie worked privately with Jesus' family to help cover the funeral costs and other expenses -- including transporting his body back to Houston. Kylie also admitted to having trouble sleeping after he passed.

And, sources told us Jesus lost 20 pounds and was complaining of chills and hot flashes leading up to his unexpected death in February.

Guerrero's sister, Gris told US Weekly that Kylie and J Lo were very gracious and contacted the family directly following Jesus' death. Kylie reportedly said she would do anything to preserve and honor Jesus' memory. Gris told the outlet she was "grateful" to Lopez for all she did for her brother.

Jesus was 34.